It is important that patients recovering from knee surgery initiate knee exercise/stretching therapy promptly after surgery to maintain knee joint flexibility and shorten the period for recovery. Patient compliance with a predetermined physical therapeutic protocol is key to early patient recovery with optimal joint flexibility and function. While there have been many devices developed to provide knee extension and exercise therapy, each has its complexities or difficulties of use that have tended to reduce patient compliance with therapeutic protocols designed for early and effective recovery.
The present invention provides a knee extension therapy apparatus that can be easily transported for patient home use, and one that can be used by the postoperative or post-trauma patient with minimal instruction and without assistance of attending medical practitioners, family members or friends. The present invention provides a simple, effective, user adaptable knee extension therapy device. The device is configured to allow the patient to lie in a comfortable recumbent position during each therapy session. That, coupled with an easy-to-use force translation pulley system for efficient and effective delivery of knee straightening forces to areas on the top of the patient's leg and areas of the shin and thigh, constitutes significant improvement over knee extension therapeutic devices that previously have been available.
There is provided in accordance with this invention a knee extension therapy apparatus for use by a patient in a recumbent position. The patient's hip corresponding to that of the leg requiring therapy rests on the surface of a base component of the device. The leg requiring extension therapy is elevated to a level above the surface upon which the patient user is resting and is held in position by a height adjustable elevated ankle support. The apparatus is preferably designed to be collapsible into an easily transported unit so that it can be used by the patient at home. The device includes a base having a patient user proximal surface for supporting the patient user's hip and a user distal portion. The apparatus also includes an ankle support member, preferably one of adjustable height mounted on a user distal portion of the base. The apparatus also includes a pulley system for translating a forced supply toward the user proximal end of the base and having a major vector component parallel to the surface of the base to a force having a major vector component substantially orthogonal to the base. The pulley system is designed to maintain the tension in the system resulting from the patient applied force. In one embodiment the pulley system enables the applied force to be translated into a mechanically advantaged force having a major component substantially orthogonal to the base. The device also includes a force transmitting element for engaging both knee proximal and knee distal portions of the patient's elevated leg. The force transmitting element has at least one user engageable/disengageable connector for attaching the element to the pulley system for applying the translated based-orthogonal force to areas on the upper surface of the patient's elevated leg proximal and distal of the elevated knee which applied forces tend to straighten the leg and extend the knee joint.
In one embodiment the knee extension therapy apparatus can be collapsed into a compact easy transported unit. In that embodiment the ankle support member is typically pivotally mounted on the user distal portion of the base and can be locked either in an upright apparatus use position or in a folded apparatus transport position. In addition, the base can be formed in two parts: a first user proximal portion and a second user distal portion wherein said portions are hingedly connected so that the user proximal portion of the base can be rotated so that the respective undersides of the user proximal and user distal portions of the base can be contacted in a apparatus transport position. In one embodiment the force transmitting element of the apparatus of the present invention comprises first and second leg straps for engaging knee proximal and knee distal portions of the patient's elevated leg, respectively, each strap having at least one user engageable/disengageable connector for attaching the straps to the pulley system. In one embodiment the leg straps have first and second user engageable/disengageable connectors for their attachment to the pulley system.
In one embodiment of the invention the pulley system comprises a line cord threaded through a main pulley mounted on the user distal portion of the base and connected to a line cord anchor located at a position intermediate to user proximal and user distal portions of the base. The pulley system typically also includes a ratcheted pulley hook attached to the line cord and a line tensioning pull cord engaged with said ratcheted pulley for applying tension to the line cord and thus the pulley system and the connected leg straps when the device is in use. The pulley system also comprises a plurality of pulley hooks positioned between the main pulley and the line cord anchor and between the line cord anchor and at least first and second line cord guides or pulleys attached to the base. Each of the pulley hooks is adapted for attachment to a connector on one or both ends of the leg straps (force transmitting elements). In one preferred embodiment the pulley system includes right hand and left hand line cords, each anchored on one end and engaged with the main pulley on and the other end connected to a ratcheted pulley hook, itself operatively engaged with a line tensioning pull cord. In one embodiment the non-anchored ends of the line cords are threaded through a line cord guide attached to the base at a position generally under the thigh of the patient's elevated leg and intermediate between the lateral edges of the base. Anchors for the line tensioning pull cord are typically located on each of the lateral edges of the user proximal portion of the base so that the pulley system can be easily utilized by patients whether they are right-handed or left-handed. Thus the line tensioning pull cord is anchored on the left lateral edge of the user proximal portion of the base when the device is set up for use by a left-handed patient user, and the tensioning pull cord is anchored at or near a right lateral edge of the user proximal portion of the base when the apparatus is set up for therapeutic use by a right handed patient user.
The pulley system can comprise either one or at least two (one for the right side and one for the left side) line cords carrying pulley hooks for connection with the leg straps for device operation. Again, the untethered end of the line cord(s) is attached to a ratcheted pulley hook operatively engaged with a line tensioning pull cord for applying force to and maintaining the resultant tension in the pulley system.